Embodiments described herein relate generally to polymer nanofiber scaffold for a heparin/fibrin based growth factor delivery system and, more particularly, to a polylactic glycolic acid nanofiber mat layered with a fibrinogen solution including heparin, fibrinogen, heparin-binding peptide, growth factor, and mesenchymal stem cells for use in tissue repair.
Growth factors drive biology and the differentiation of mesenchymal stem cells. Mesenchymal stem cells combined with a sustained supply of appropriate growth factors at the site of a structural tissue injury aid in repairing the injury.
A first prior art growth factor delivery system is fibrin gel encapsulating a mixture of heparin, growth factor, and mesenchymal stem cells. A second prior art growth factor delivery system is disclosed in U.S. Pat. No. 6,468,731 issued Oct. 22, 2002 and U.S. Pat. No. 6,960,452 issued Nov. 1, 2005, the entire disclosures of which are incorporated herein by reference. In this second prior art growth factor delivery system, a heparin-binding peptide or protein is added to the fibrin gel, and the heparin-binding peptide binds to the fibrin molecules and heparin molecules. The growth factor is bound to the heparin, and mesenchymal stem cells are mixed into the fibrin gel. The addition of the heparin-binding peptide extends the release of the growth factor. Fibrin gel alone is difficult to handle, surgically implant, and retain at an injury site due to its gelatinous consistency.